Push-on retainers



Dec. 6, 1966 H. KRAMER PUSHON RETAINERS Filed Nov. 24, 1964 INVENTOR/YM/-WV/(f/PHME?,

ATTORNEY United States Patent O M 3,289,523 PUSH-0N RETAHJERS HymanKramer, 2764 IE. 16th St., Brooklyn, NX. Filed Nov. 24, 1964, Ser. No.413,509 4 Claims. (Cl. SS-SS) The present application for Letters Patentis, particularly in its article aspect, a continuation-in-part ofapplication Serial No. 327,672, filed December 3, 1963, now Patent No.3,215,025.

This invention relates to improvements in push-on retainers and is moreparticularly directed to an end cap-type retaining device which isadapted to secure itself in endcapping relation to a shaft, spindle orlike carrier member when simply pushed over the end thereof.

Continuing experience with end-cap type retainers presently available onthe market as wellas with the various improved forms thereof accordingto my aforesaid application, has demonstrated a feature of objectioncommon to all, namely, that of the difficulty in initially centeringthem and thereafter engaging them with their carrier members due to theinterference to centering and motion of retainer on carrier end stemmingfrom the location of the locking prongs with which said retainers areprovided and on whose action depends the holding power of the retainerswith respect to their carrier members. In explanation, in the priorforms and makes of push-on retainers, it was conventional to locate thelocking prongs thereof so that their inner free ends which project intothe interior of the retainer crown portion are disposed closely adjacentthe juncture of said crown portion with the brim or washer-like flangeportion thereof. In this location, the inner ends of the locking prongsexert a degree of resistance to initial centering of the retainer oncarrier-member end which can be substantial if the internal diameter ofthe retainer crown portion closely approximates the external diameter ofthe carrier member, which again is necessary for proper locking actionof the prongs. And if the retainers are not properly centered initially,either an undue amount of force is required to finally set them or theyare likely to assume a cocked position on their carrier members whenfinally pushed to their final position, which latter is highlyobjectionable.

A main object of the present invention, therefore, is the provision of apush-on end cap-type of retainer constructed and arranged as to overcomethe above-noted objectionable feature of the prior retainer of similartype.

A more particular object of the invention is the provision of a push-onend cap-type of retainer whose locking prongs are effectively locatednearer the closed end of the crown portion thereof than are the lockingprongs of the prior retainers of similar type, which results inappreciable unobstructed axial space being provided at the end of thecrown portion adjacent the brim or washerlike flange portion of thedevice, as in turn facilitates initial centering of the retainer on ashaft, spindle or like carrier-member end.

The above and other objects and advantages of the present invention willappear from the following more detailed description thereof, in whichreference is had to the accompanying illustrative drawings, wherein:

FIG. l is a plan view of a push-on end cap-type retainer according tothe invention, looking into the open end of the crown portion and thusonto the under or working facel of the brim or retaining flange portionthereof;

FIGS. 2 and 3 are sections taken on lines 2--2 and 3 3, respectively, ofFIG. l;

FIG. 4 is a greatly enlarged `fragmentary perspective View, looking intoone of the crown embossments and onto the inside face of one of thelocking prongs of a 31,2%,5235 Patented Dec, 6, H966 ICC push-on endcap-type retainer of the invention, this View being intended toillustrate the substantial setting-back of the locking prongs within thecrown portion thereof which characterizes the retainer of the invention;

FIG. 5 is a plan View which illustrates the progressive formation ofpush-on end cap-type retainers of the invention from a strip of suitableretainer material such as sheet steel; and

FIG, 6 is a section taken along line 6-6 of FIG. 5.

Referring to FIGS. 1 4, such illustrate that a push-on end cap-typeretainer of the invention basically comprises a cap or crown portionIt), an integral brim or retainingflange portion l2 (said portions to behereinafter for convenience referred to as the crown and the retainingflange, respectively) and circumferentially spaced (usuallydiametrically opposed) integral locking prongs 14a, 14h whose free endsextend radially and along arcs of a circle of lesser diameter than thatof the crown interior into the interior space of said crown lil by anamount and at an inclination such as to permit the retainer to bereadily pushed onto the end of a shaft, spindle or like carrier memberhaving diameter slightly less than that of the internal diameter of thecrown li), and thereafter to enable the retainer to self-lock itself tosaid carrier member by virtue of the ability of the arcuate free-endedges of the locking prongs to bite into the material making up theperipheral surface of said member, under a thrust force or forcesdirected against the under face of the retaining flange and acting in adirection as tends to separate the retainer as a whole from said carriermember.

According to the present invention, the integral locking prongs 14a, Mb,rather than being struck out from the material of the crown and/ or brimat locations thereof such that they flex about root lines disposedeither within the area -of the retaining flange or Which substantiallycoincide with the line of juncture between the crown and retainingflange, as is conventional in the prior pushon end cap-type retainers,are instead not only struck out from portions of the crown wall whichare .spaced a substantial distance axially inwardly or toward the closedend lila of the crown so that the prongs flex about root lines which areset `back into the crown, but also are struck `out from the material ofradially outwardly projecting -bulges or embossments purposefully formedin the crown wall at diametrically opposed locations thereof, thus tospace :said root lines outwardly of the circle of the crown. It will beunderstood that the expression root lines as herein used means theimaginary lines which extend across the roots of the prongs at thejunctures of said prongs and the part, i.e. crown, retaining flangeand/or embossments to be described, from which said prongs extend andabout which said prongs flex.

More particularly, it is a feature of the invention that outwardlyprojecting embossments designated l-S and Ztl in the various views areformed in the crown wall and retaining flange at preferablydiametrically opposite areas thereof by drawing same fro-m the metal ofthe crown wall and retaining flange beginning substantially inwardly -ofthe plane of the retaining flange l2 and extending radially Aoutwardlyinto said flange. As best seen in FIG. 4, said embossments 18 and 2liare each defined by circumferentially `spaced-apart side walls a, b, aconnecting outer wall c and an end wall d which merges into the crownwall at a location which is spa-ced a substantial distance inwardly ofthe crown from the line of juncture of said crown and said retainingflange. Thus, the embossments 18, 20 each has general U-section in bothtransverse and vertical planes extending through same and, as will beevident from a consideration of FIG. 4 in particular, the embossmentsopen both into the crown interior and downwardly through the retainingflange 12.

Upon formation of the embossments I8, 2d as aforesaid,

#.9 it becomes a relatively simple matter to form the locking prongs Mn,llrtb `by in effect cutting the end walls d of the embossments `awayfrom both crown walls with which they merg-e and from the embossmentside walls a, b to which said end walls lwere earlier integrally joined,along generally U-shaped lines of cut designated Mc in FIG. 2.Preferably, the transverse lines of cut separating the embossment endwalls d from the crown wall, rather than being disposed precisely at thejuncture of said end walls d and the crown wall, are disposed a smalldistance away from said juncture in the direction of the crown end walla, thus to give some added length to the locking prongs being soform-ed, and the Vside lines of :cut extend back into the embossmentside walls for a depth such as to provide a workable prong. Suchcuttingaaway operation frees the inner end portions of the embossmentend walls d yboth from the crnbossrnent side walls a and b and from thecrown wall, `so that such end portions now tend to assume theconfiguration of conventional prongs. Finally, the so cut-free prongsare given the requisite inclination as enables them to act as lockingprongs, that is to say, they are coned inwardly into the crown interiorspace at an angle which does not exceed the so-called friction angle. Bythe term friction angle as here employed is meant the angle whichenables the locking prongs 14a, 14h to flex radially outwardly more orless freely when the retainer is being pushed onto the end of itscarrier member in its assembly thereon, but to straighten and therebythe free-end edges thereof to bite into and grip to the material makingup the peripheral surface of the carrier member when a thrust force isapplied to the retaining flange 12 in direction as tends to cause theretainer as a whole to move axially away from and separate itself fromsaid carrier member.

Push-on end cap-type retaining devices according to the presentinvention are thus characterized by locking prongs which project intothe interior space of the crown or cap portion at locations along theaxial dimension thereof which are spaced a substantial distance from theplane of the retaining fiange portion of such devices. Hence, endcap-type retaining devices as herein constructed and arranged can bemore readily initially centered on an moved over the ends of theirshafts, spindles and the like than was possible with the prior retainingdevices of similar type whose locking prongs projected into the circledefining the interior space of the crown portion thereof at locationsclosely adjacent the juncture of the crown and retaining flange portionsthereof, with the result that said locking prongs interfered with boththe quick and easy initial centering and the final placement of theretainer on its shaft or other carrier member.

Push-on end cap retaining devices according to the invention lendthemselves to cheap, speedy manufacture from a strip ST of sheet steelof the proper gauge in a progressive compound blanking, drawing andpiercing die. While such a die is not shown, its progressive action inblanking out each starting disc-form blank SD from which an end cap asherein proposed is ultimately fashioned, in progressively deep-drawingthe crown portion 1f) in a plurality of stages (in practice foursuccessive draws) from said blank, in further drawing the diametricallyopposed, radially-outwardly projecting embossments 1S, Ztl from sidewall areas of the crown portion and adjacent areas of the blank, inpiercing said embossments and crown wall in manner as to cut the lockingprongs 14a, 1411 therefrom as the strip is moved progressively throughthe die, and finally in cutting away the finished cap-type fastener fromits blank, will, it is believed, be readily apparent to persons skilledin the art from a consideration of FIGS. 5 and 6. As alsodiagrammatically shown in said views, it will be understood that theend-cap blanks from the starting disc blankingout stage thereof throughthe prong-piercing or cutting out stage are connected to the strip ST atdiametrically opposed portions thereof by connecting webs W, W1, and

that the final end caps are struck out from said blanks along circularlines of severance lying within the outer partcircular lines of cutwhich define said blanks. It will also be observed that the embossrnents18, 2d are formed on the same diameter as that of the webs W, W1 whichconnect the blanks SD to the strip, a feature designed to insureadequate metal into which the embossment bottom portions may extend.Preferably, the bending of the locking prongs 14a, llib to their properconing angle is also effected in the die, so that the end caps struckfrom the blanks may be removed from the die as completed articlesseparately from the scrap discharging therefrom.

While the cap-type retainer of the invention has been described andillustrated as having a closed crown top or inner end litlzz, it mayalso be fashioned without said top or with an apertured top, thus to bemovable to any desired axial position along the length of a shaft,spindle or like carrier member required for a particular fastenerapplication. lt is also within the scope and purview of the presentinvention to arrange the locking prongs 14a, ift-b so that they lie on ahelix corresponding to the pitch of the threads of a bolt, in which casea retainer according to the invention is capable of serving as a push-onsecuring nut for said bolt.

Without further analysis, it will be appreciated that push-on endcap-type retainers according to the invention satisfies the objectivesof the invention in effective and thoroughly dependable manner. However,as many changes coul-d be made in carrying out the above constructionswithout departing from the scope of the invention, it is intended thatall matter contained in the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

I claim:

i. An end cap-type retainer device for push-on assembly on the end of ashaft and like carrier member comprising: a cap-form body having asubstantially cylindrical crown portion defining a shaft-receivingopening and an integral brim-like retaining flange extending radiallyoutwardly from an end thereof and adapted to take thrust loads appliedin axial direction against its under face, a plurality ofcircumferentially spaced, radially outwardly projecting embossrnentsformed in the side wall of said crown portion and terminating at theirends remote from said fiange in substantially plane end walls, andlocking prongs comprising areas struck out from at least said end wallsand having length such that their free ends extend radially inwardlyinto the interior space of said crown portion, and said locking prongsfurther having inclination such that said prongs will fiex outwardlyduring push-on assembly of the device on said carrier member but willtend to assume radial positions in which the freeend edges thereof biteinto the material of the peripheral surface of said member when thrustloads are applied to the under face of said retaining flange asaforesaid.

2. An end cap-type retainer device according to claim l, wherein saidembossrnents are formed in the wall of the crown portion adjacent theline of juncture thereof with the retaining flange and extend axiallytherefrom into said crown portion and their said plane end walls connectto the crown wall at locations which are spaced an appreciable axiallyaway from said line of juncture.

3. An end cap-type retainer device according to claim l, wherein saidlocking prongs each comprises an area struck out from an embossment endwall and a contiguous area of the crown portion Wall which extends fromsaid embossment in the direction of the top of said crown portion.

Li. An end cap-type retainer device according to claim 2, wherein saidembossrnents are hollow and are so formed that they open at their otherend through the retaining flange and inwardly to the interior space ofthe crown portion.

(References on following page) 5 6 References Cited by the Examiner2,880,641 4/ 1959 Sislik 85-35 UNITED STATES PATENTS 3,153,972 10/1964Holton 85-35 944,643 12/1909 White 85-36 THOMAS F. CALLAGHAN, PrimaryExaminer. 2,135,418 11/1938 Timmerman 72-335 2,309,942

2/1943 Ekstedt et al. '72* 33 5 5 M. PARSONS, JR., Assistant Examiner.

1. AN END CAP-TYPE RETAINER DEVICE FOR PUSH-ON ASSEMBLY ONE THE END OF ASHAFT AND LIKE CARRIER MEMBER COMRISING: A CAP-FORM BODY HAVING ASUBSTANTIALLY CYLINDRICAL CROWN PORTION DEFINING A SHAFT-RECEIVINGOPENING AND AN INTEGRAL BRIM-LIKE RETAINING FLANGE EXTENDING RADIALLYOUTWARDLY FROM AN END THEREOF AND ADAPTED TO TAKE THRUST LOADS APPLIEDIN AXIAL DIRECTION AGAINST ITS UNDER FACE, A PLURALITY OFCIRCUMFENENTIALLY SPACED, RADIALLY OUTWARDLY PROJECITNG EMBOSSMENTSFROMED IN THE SIDE WALL OF SAID CROWN PORTION AND TERMINATING AT THEIRENDS REMOTE FROM SAID FLANGE IN SUBSTANTIALLY PLANE END WALLS, ANDLOCKING PRONGS COMPRISING AREAS STRUCK OUT FROM AT